The vihuela is not a viol, it is a sort of lute. Vihuela and lute coexisted in Spain but the composers wrote only for the former. The works played in this recording were mainly published between 1535 and 1554; Daza's book (1576) and a collection of other authors (1593) mark the end of the era of the vihuela. Then the instrument lent its shape to the guitar, as you can infer from the cover of the CD.